There are known in the prior art various types of skier's exercise devices used to simulate the motions and conditions incident to making parallel turns, in which the skis are maintained parallel to each other, while shifting body weight from one ski to another, moving the uphill ski to a position forward of the downhill ski and edging the skis into the hill.
In one such device, disclosed in Izzo U.S. Pat. No. 3,374,782 issued Mar. 26, 1968, a skier wearing ski boots stands on two narrow platforms which are mechanically driven by a motor, via an appropriate gear and cam mechanism, through predetermined and prescribed angles to simulate parallel turns. While this device may simulate parallel turns, it does not teach the active coordination and total involvement of the body which initiates and executes each turn leading directly and immediately into the next. As the skier does not initiate any of the action, his muscles are not involved in generating the turns as in actual skiing. Hence, the muscular compression and extension required in actual parallel turning is absent. In addition, the skier is required to wear ski boots, which is an inconvenience. The gear and cam motor arrangement render this device inordinately expensive to manufacture and repair.
Poulin U.S. Pat. No. 3,461,857, issued Aug. 19, 1969, discloses another device in which a turntable, mounted for rotation on an inclined support plate, carries a pair of foot supports which are also connected to the support plate, upon which the skier stands. The turntable may then be rotated either by the skier or by an electric motor, moving the foot supports to simulate the positions of skis during parallel turns. While this device permits the skier to initiate the action, since the foot supports are in fixed positions relative to each other, it does not provide for the independent alternating fore-and-aft movement of each ski which occurs with each turn. Neither does Poulin provide for simulating the edging action which takes place in actual parallel turns. Poulin's foot supports are kept in a constant horizontal attitude in spite of the angle of the turntable plane. It will thus be seen that Poulin does not simulate the actual component movements of a parallel turn.
Still another device is disclosed in Poppenberger U.S. Pat. No. 3,834,693 issued Sept. 10, 1974 in which a pair of ski boot simulating devices, on which the skier stands, are secured by corresponding rotatable and vertically movable double hinges and cylinders to corresponding horizontal platforms. The platforms carry wheels which are received in the tracks of a pair of frames, permitting movement in a first horizontal direction. The frames also carry wheels, which are received in a main support track, permitting movement in a second horizontal direction perpendicular to the first. The main support track is secured to a disc which can be rotated in either direction in a horizontal plane about its center. While this device may simulate some of the movements associated with parallel turns, it fails to allow for the shifting of weight from one ski to another. It appears that if the proper pressure were exerted against either platform, it would slam shut or its wheels would leave the tracks. In addition, the double-hinged plates do not accurately simulate edging, as the hinge acts as the pivotal point in the edging action which is not the action of the skiis on snow. Moreover, the cylinder, which is intended to provide an up-and-down movement to the ski boot simulating device, also provides an additional rotation on a vertical axis extending through its center. This additional rotation may counteract the pressure applied during edging and prevent movement of the turntable.
Poppenberger's tiered arrangement also appears extremely precarious, presenting the possibility of accident to the user if, for example, one of the sixteen wheels should fail. This would also render the device useless, as would the failure of any of the four hinges or two cylinders. It should also be noted that the number of parts of this device render the cost of manufacture and assembly prohibitive, and, that special shoes must be worn by the user.